Here is a script from Tcad 2.0b
# Program: dxf (an autocad's dxf to tk's canvas converter)
# Author: Tuan T. Doan # =========================================================================
# Copyright 1993 Tuan T. Doan
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appear in all copies. Tuan
# Doan make no representations about the suitability of this software
# for any purpose. It is provided "as is" without express or implied
# warranty. If you do use any part of the software, I would like to
# know about it. Please send me mail at [email protected]
#
# DXF format is copyrighted by Autodesk, Inc.
# =========================================================================
set auto_path ". $auto_path"
set gvar(unit) p
set gvar(scale) 1.0
proc _gettuple {fd} {
# read in two lines; first line = groupcode, second line = groupvalue
global gvar
set gvar(groupcode) [string trim [gets $fd]]
set gvar(groupvalue) [string trim [gets $fd]]
# puts stdout "$gvar(groupcode) $gvar(groupvalue) - " nonewline
}
proc _circle {fd} {
# we already read: 0,CIRCLE ; continue to read in circle info until see 0
# interested in: 10=xcenter, 20=ycenter, 40=radius
global gvar
while {! [eof $fd]} {
_gettuple $fd
case $gvar(groupcode) in {
{0} {return "[expr $x-$r]$gvar(unit) [expr $y-$r]$gvar(unit) [expr $x+$r]$gvar(unit) [expr $y+$r]$gvar(unit) -outline black"}
{10} {set x $gvar(groupvalue)}
{20} {set y [expr {-1 * $gvar(groupvalue)}]}
{40} {set r $gvar(groupvalue)}
{62} {set gvar(color) $gvar(groupvalue)}
}
}
}
proc _line {fd} {
# we already read: 0,LINE ; continue to read in line info until see 0
# interested in: 10=xpoint1, 20=ypoint1, 11=xpoint2, 21=ypoint2
global gvar
while {! [eof $fd]} {
_gettuple $fd
case $gvar(groupcode) in {
{0} {return "${x1}$gvar(unit) ${y1}$gvar(unit) ${x2}$gvar(unit) ${y2}$gvar(unit) -fill black"}
{10} {set x1 $gvar(groupvalue)}
{20} {set y1 [expr {-1 * $gvar(groupvalue)}]}
{11} {set x2 $gvar(groupvalue)}
{21} {set y2 [expr {-1 * $gvar(groupvalue)}]}
{62} {set gvar(color) $gvar(groupvalue)}
}
}
}
proc _triangle {fd} {
# we already read: 0,3DFACE ; continue to read in surface info until see 0
# interested in: 10=xpoint1, 20=ypoint1, 11=xpoint2, 21=ypoint2
# 12=xpoint3, 22=ypoint3, 13=xpoint3, 23=ypoint3
# if last point 3 is same as point 4, we want only points 1-3
global gvar
set x1 ""; set x2 ""; set x3 ""; set x4 ""
set y1 ""; set y2 ""; set y3 ""; set y4 ""
while {! [eof $fd]} {
_gettuple $fd
case $gvar(groupcode) in {
{0} {if {$x3==$x4 && $y3==$y4} {
puts stdout "3dtri"
# return "polygon ${x1}$gvar(unit) ${y1}$gvar(unit) ${x2}$gvar(unit) ${y2}$gvar(unit) ${x3}$gvar(unit) ${y3}$gvar(unit) -fill white"
return "line ${x1}$gvar(unit) ${y1}$gvar(unit) ${x2}$gvar(unit) ${y2}$gvar(unit) ${x3}$gvar(unit) ${y3}$gvar(unit) -fill black"
} else {
puts stdout "3dpoly"
# return "polygon ${x1}$gvar(unit) ${y1}$gvar(unit) ${x2}$gvar(unit) ${y2}$gvar(unit) ${x3}$gvar(unit) ${y3}$gvar(unit) ${x4}$gvar(unit) ${y4}$gvar(unit) -fill white"
return "line ${x1}$gvar(unit) ${y1}$gvar(unit) ${x2}$gva